U.S. patent application number 13/040198 was filed with the patent office on 2011-06-23 for pen-type injector.
Invention is credited to Robert Perkins, David Aubrey Plumptre, Robert Frederick Veasey.
Application Number | 20110152784 13/040198 |
Document ID | / |
Family ID | 9954010 |
Filed Date | 2011-06-23 |
United States Patent
Application |
20110152784 |
Kind Code |
A1 |
Veasey; Robert Frederick ;
et al. |
June 23, 2011 |
PEN-TYPE INJECTOR
Abstract
The present invention relates to injectors, such as pen-type
injectors, that provide for administration of medicinal products
from a multidose-cartridge and permit a user to set the delivery
dose. The injector may include a housing, a piston rod adapted to
operate through the housing, a dose dial sleeve located between the
housing and the piston rod, and a drive sleeve located between the
dose dial sleeve and the piston rod. The dose dial sleeve may have
a helical thread of first lead and the drive sleeve may have a
helical groove of second lead. The first lead of the helical thread
and the second lead of the helical groove may be the same.
Inventors: |
Veasey; Robert Frederick;
(Warwickshire, GB) ; Perkins; Robert;
(Warwickshire, GB) ; Plumptre; David Aubrey;
(Worcestershire, GB) |
Family ID: |
9954010 |
Appl. No.: |
13/040198 |
Filed: |
March 3, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11483546 |
Jul 11, 2006 |
7918833 |
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13040198 |
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10790225 |
Mar 2, 2004 |
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11483546 |
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Current U.S.
Class: |
604/207 |
Current CPC
Class: |
A61M 5/31528 20130101;
A61M 5/31575 20130101; A61M 5/31533 20130101; A61M 5/31551
20130101; A61M 2205/581 20130101; A61M 5/31541 20130101; A61M 5/32
20130101; A61M 5/31578 20130101; A61M 5/3157 20130101; A61M 5/31563
20130101; A61M 5/24 20130101; A61M 5/31585 20130101; A61M 5/31568
20130101; A61M 5/3156 20130101; A61M 2005/3126 20130101; A61M
5/31535 20130101; A61M 5/31546 20130101; A61M 5/31593 20130101;
A61M 5/31536 20130101; A61M 2205/582 20130101; A61M 5/31565
20130101; A61M 2005/2407 20130101 |
Class at
Publication: |
604/207 |
International
Class: |
A61M 5/31 20060101
A61M005/31 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 3, 2003 |
GB |
0304822.0 |
Claims
1. A dispensed dose indicator mechanism for a pen-type injector,
comprising: a housing having an internal surface with one or more
splines; a drive sleeve configured to move both axially and
rotationally relative to the internal surface of the housing, the
drive sleeve having an outer surface on which a thread is disposed;
and a nut engaged with the thread, where the nut is fixed
rotationally with respect to the housing and is axially
displaceable along the thread when the drive sleeve is rotated.
2. The dispensed dose indicator mechanism of claim 1 further
characterized in that the outer surface of the drive sleeve has a
first radially extending flange and a second radially extending
flange, the thread is disposed between the two flanges.
3. The dispensed dose indicator mechanism of claim 1 where the nut
is keyed to the one or more splines on the internal surface of the
housing to prevent the nut from rotating relative to the housing
while allowing axial movement relative to the housing.
4. The dispensed dose indicator mechanism of claim 1 where the nut
is a half nut.
5. The dispensed dose indicator mechanism of claim 1 where axially
displacement of the nut is indicative of dispensed doses.
6. The dispensed dose indicator mechanism of claim 1 where the
thread is proportional to available doses of medicament contained
in a cartridge attached to the pen-type injector.
7. The dispensed dose indicator mechanism of claim 1 where a first
radial stop on the nut engages a second radial stop on the second
flange when a final dose of medicament is dispensed from a
cartridge attached to the pen-type injector.
8. The dispensed dose indicator mechanism of claim 1 where a radial
stop on the nut engages a radial stop on the first flange
indicative of a cartridge full position.
9. A method of determining a final dose of a medicament contained
in a cartridge in a pen-type injector comprising, providing a
housing containing a drive sleeve having a nut threadedly engaged
to an outer surface of the drive sleeve between a first and second
flange; configuring the nut and thread to be indicative of
dispensed doses; and configuring the second flange to engage the
nut when a final dose of medicament is dispensed from a cartridge
attached to the pen-type injector.
10. The method of claim 9 further comprising configuring the nut
and second flange to prevent the drive sleeve from rotating when
the final dose of medicament is dispensed.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent
application Ser. No. 11/483,546, filed Jul. 11, 2006, which is a
continuation of U.S. patent application Ser. No. 10/790,225, filed
Mar. 2, 2004, which claims priority to GB 0304822.0 filed Mar. 3,
2003, the entire contents of which are incorporated herein by
reference.
BACKGROUND
[0002] The present invention relates to pen-type injectors, that
is, to injectors of the kind that provide for administration by
injection of medicinal products from a multidose cartridge. In
particular, the present invention relates to such injectors where a
user may set the dose.
[0003] Such injectors have application where regular injection by
persons without formal medical training occurs. This is
increasingly common amongst those having diabetes where
self-treatment enables such persons to conduct effective management
of their diabetes.
[0004] These circumstances set a number of requirements for
pen-type injectors of this kind. The injector must be robust in
construction, yet easy to use both in terms of the manipulation of
the parts and understanding by a user of its operation. In the case
of those with diabetes, many users will be physically infirm and
may also have impaired vision. Where the injector is to be
disposable rather than reusable, the injector should be cheap to
manufacture and easy to dispose of (preferably being suitable for
recycling).
SUMMARY
[0005] It is an advantage of the present invention that an improved
pen-type injector is provided.
[0006] According to a first aspect of the present invention, a
pen-type injector comprises
[0007] a housing;
[0008] a piston rod adapted to operate through housing;
[0009] a dose dial sleeve located between the housing and the
piston rod, the dose dial sleeve having a helical thread of first
lead;
[0010] a drive sleeve located between the dose dial sleeve and the
piston rod, the drive sleeve having a helical groove of second
lead;
[0011] characterized in that the first lead of the helical thread
and the second lead of the helical groove are the same.
[0012] Preferably, the piston rod has a first threaded portion at a
first end and a second threaded portion at a second end;
[0013] an insert or radially inwardly extending flange is located
in the housing and through which the first threaded portion of the
piston rod may rotate;
[0014] the dose dial sleeve being rotatable with respect to the
housing and the insert; [0015] the drive sleeve being releasably
connected to the dose dial sleeve and connected to the piston rod
for rotation with respect thereto along the second threaded portion
of the piston rod;
[0016] a button is located on the dose dial sleeve and rotatable
with respect to the does dial sleeve; and [0017] clutch means are
provided which upon depression of the button permit rotation
between the dose dial sleeve and the drive sleeve.
[0018] Preferably, the injector further comprises a nut which is
rotatable with respect to the drive sleeve and axially displaceable
but not rotatable with respect to the housing.
[0019] More preferably, the drive sleeve is provided at a first end
with first and second flanges with an intermediate thread between
the first and second flanges, the nut being disposed between the
first and second flanges and keyed to the housing by spline means.
Additionally, a first radial stop may be provided on a second face
of the nut and a second radial stop may be provided on a first face
of the second flange.
[0020] Preferably, the first thread of the piston rod is oppositely
disposed to the second thread of the piston rod.
[0021] Preferably, a second end of the clutch is provided with a
plurality of dog teeth adapted to engage with a second end of the
dose dial sleeve.
[0022] Preferably, the pen-type injector further includes clicker
means disposed between the clutch means and spline means provided
on the housing.
[0023] More preferably, the clicker means comprises a sleeve
provided at a first end with a helically extending arm, a free end
of the arm having a toothed member, and at a second end with a
plurality of circumferentially directed saw teeth adapted to engage
a corresponding plurality of circumferentially saw teeth provided
on the clutch means.
[0024] Alternatively, the clicker means comprises a sleeve provided
at a first end with at least one helically extending arm and at
least one spring member, a free end of the arm having a toothed
member, and at a second end with a plurality of circumferentially
directed saw teeth adapted to engage a corresponding plurality of
circumferentially directed saw teeth provided on the clutch
means.
[0025] Preferably, the main housing is provided with a plurality of
maximum dose stops adapted to be abutted by a radial stop provided
on the dose dial sleeve. More preferably, at least one of the
maximum dose stops comprises a radial stop located between a
helical rib and spline means provided at a second end of the
housing. Alternatively, at least one of the maximum dose stops
comprises a part of a raised window portion provided at a second
end of the housing.
[0026] Preferably, the dose dial sleeve is provided with a
plurality of radially extending members adapted to abut a
corresponding plurality of radial stops provided at a second end of
the housing.
BRIEF DESCRIPTION OF THE FIGURES
[0027] The invention will now be described with reference to the
accompanying drawings in which:
[0028] FIG. 1 shows a sectional view of a pen-type injector in
accordance with the present invention in a first, cartridge full,
position;
[0029] FIG. 2 shows a sectional view of the pen-type injector of
FIG. 1 in a second, maximum first dose dialed, position;
[0030] FIG. 3 shows a sectional view of the pen-type injector of
FIG. 1 in a third, first maximum first dose dispensed,
position;
[0031] FIG. 4 shows a sectional view of the pen-type injector of
FIG. 1 in a fourth, final dose dialed, position;
[0032] FIG. 5 shows a sectional view of the pen-type injector of
FIG. 1 in a fifth, final dose dispensed, position;
[0033] FIG. 6 shows a cut-away view of a first detail of the
pen-type injector of FIG. 1;
[0034] FIG. 7 shows a partially cut-away view of a second detail of
the pen-type injector of FIG. 1;
[0035] FIG. 8 shows a partially cut-away view of a third detail of
the pen-type injector of FIG. 1;
[0036] FIG. 9 shows the relative movement of parts of the pen-type
injector shown in FIG. 1 during dialing up of a dose;
[0037] FIG. 10 shows the relative movement of parts of the pen-type
injector shown in FIG. 1 during dialing down of a dose;
[0038] FIG. 11 shows the relative movement of parts of the pen-type
injector shown in FIG. 1 during dispensing of a dose;
[0039] FIG. 12 shows a partially cut-away view of the pen-type
injector of FIG. 1 in the second, maximum first dose dialed,
position;
[0040] FIG. 13 shows a partially cut-away view of the pen-type
injector of FIG. 1 in the fourth, final dose dialed, position;
[0041] FIG. 14 shows a partially cut-away view of the pen-type
injector of FIG. 1 in one of the first, third or fifth
positions;
[0042] FIG. 15 shows a cut-away view of a first part of a main
housing of the pen-type injector of FIG. 1; and
[0043] FIG. 16 shows a cut-away view of a second part of the main
housing of the pen-type injector of FIG. 1.
DETAILED DESCRIPTION
[0044] Referring first to FIGS. 1 to 5, there may be seen a
pen-type injector in accordance with the present invention in a
number of positions.
[0045] The pen-type injector comprises a housing having a first
cartridge retaining part 2, and second main housing part 4. A first
end of the cartridge retaining means 2 and a second end of the main
housing 4 are secured together by retaining features 6. In the
illustrated embodiment, the cartridge retaining means 2 is secured
within the second end of the main housing 4.
[0046] A cartridge 8 from which a number of doses of medicinal
product may be dispensed is provided in the cartridge retaining
part 2. A piston 10 is retained in a first end of the cartridge
8.
[0047] A removable cap 12 is releasably retained over a second end
of the cartridge retaining part 2. In use the removable cap 12 can
be replaced by a user with a suitable needle unit (not shown). A
replaceable cap 14 is used to cover the cartridge retaining part 2
extending from the main housing 4. Preferably, the outer dimensions
of the replaceable cap 14 are similar or identical to the outer
dimensions of the main housing 4 to provide the impression of a
unitary whole when the replaceable cap 14 is in position covering
the cartridge retaining part 2.
[0048] In the illustrated embodiment, an insert 16 is provided at a
first end of the main housing 4. The insert 16 is secured against
rotational or longitudinal motion. The insert 16 is provided with a
threaded circular opening 18 extending therethrough. Alternatively,
the insert may be formed integrally with the main housing 4 the
form of a radially inwardly directed flange having an internal
thread.
[0049] A first thread 19 extends from a first end of a piston rod
20. The piston rod 20 is of generally circular section. The first
end of the piston rod 20 extends through the threaded opening 18 in
the insert 16. A pressure foot 22 is located at the first end of
the piston rod 20. The pressure foot 22 is disposed to abut a
second end of the cartridge piston 10. A second thread 24 extends
from a second end of the piston rod 20. In the illustrated
embodiment the second thread 24 comprises a series of part threads
rather than a complete thread. The illustrated embodiment is easier
to manufacture and helps reduce the overall force required for a
user to cause medicinal product to be dispensed.
[0050] The first thread 19 and the second thread 24 are oppositely
disposed. The second end of the piston rod 20 is provided with a
receiving recess 26.
[0051] A drive sleeve 30 extends about the piston rod 20. The drive
sleeve 30 is generally cylindrical. The drive sleeve 30 is provided
at a first end with a first radially extending flange 32. A second
radially extending flange 34 is provided spaced a distance along
the drive sleeve 30 from the first flange 32. An intermediate
thread 36 is provided on an outer part of the drive sleeve 30
extending between the first flange 32 and the second flange 34. A
helical groove 38 extends along the internal surface of the drive
sleeve 30. The second thread 24 of the piston rod 20 is adapted to
work within the helical groove 38.
[0052] A first end of the first flange 32 is adapted to conform to
a second side of the insert 16.
[0053] A nut 40 is located between the drive sleeve 30 and the main
housing 2, disposed between the first flange 32 and the second
flange 34. In the illustrated embodiment the nut 40 is a half-nut.
This assists in the assembly of the injector. The nut 40 has an
internal thread matching the intermediate thread 36. The outer
surface of the nut 40 and an internal surface of the main housing 4
are keyed together by splines 42 (see FIGS. 10, 11, 15 and 16) to
prevent relative rotation between the nut 40 and the main housing
4, while allowing relative longitudinal movement therebetween.
[0054] A shoulder 37 is formed between a second end of the drive
sleeve 30 and an extension 38 provided at the second end of the
drive sleeve 30. The extension 38 has reduced inner and outer
diameters in comparison to the remainder of the drive sleeve 30. A
second end of the extension 38 is provided with a radially
outwardly directed flange 39.
[0055] A clicker 50 and a clutch 60 are disposed about the drive
sleeve 30, between the drive sleeve 30 and a dose dial sleeve 70
(to be described below).
[0056] The clicker 50 is located adjacent the second flange 34 of
the drive sleeve 30. The clicker 50 is generally cylindrical and is
provided at a first end with a flexible helically extending arm 52
(shown most clearly in FIG. 6). A free end of the arm 52 is
provided with a radially directed toothed member 54. A second end
of the clicker 50 is provided with a series of circumferentially
directed saw teeth 56 (of FIG. 7). Each saw tooth comprises a
longitudinally directed surface and an inclined surface.
[0057] In an alternative embodiment (not shown) the clicker means
further includes at least one spring member. The at least one
spring member assists in the resetting of the clutch means 60
following dispense.
[0058] The clutch means 60 is located adjacent the second end of
the drive sleeve 30. The clutch means 60 is generally cylindrical
and is provided at a first end with a series of circumferentially
directed saw teeth 66 (see FIG. 7). Each saw tooth comprises a
longitudinally directed surface and an inclined surface. Towards
the second end 64 of the clutch means 60 there is located a
radially inwardly directed flange 62. The flange 62 of the clutch
means 60 is disposed between the shoulder 37 of the drive sleeve 30
and the radially outwardly directed flange 39 of the extension 38.
The second end of the clutch means 60 is provided with a plurality
of dog teeth 65 (FIG. 8). The clutch 60 is keyed to the drive
sleeve 30 by way of splines (not shown) to prevent relative
rotation between the clutch 60 and the drive sleeve 30.
[0059] In the illustrated embodiment, the clicker 50 and the clutch
60 each extend approximately half the length of the drive sleeve
30. However, it will be understood that other arrangements
regarding the relative lengths of these parts are possible.
[0060] The clicker 50 and the clutch means 60 are normally engaged,
that is as shown in FIG. 7.
[0061] A dose dial sleeve 70 is provided outside of the clicker 50
and clutch means 60 and radially inward of the main housing 4. A
helical groove 74 is provided about an outer surface of the dose
dial sleeve 70.
[0062] The main housing 4 is provided with a window 44 through
which a part of the outer surface of the dose dial sleeve may be
seen. The main housing 4 is further provided with a helical rib 46,
adapted to be seated in the helical groove 74 on the outer surface
of the dose dial sleeve 70. The helical rib 46 extends for a single
sweep of the inner surface of the main housing 4. A first stop 100
is provided between the splines 42 and the helical rib 46 (FIG.
15). A second stop 102, disposed at an angle of 180.degree. to the
first stop 100 is formed by a frame surrounding the window 44 in
the main housing 4 (FIG. 16).
[0063] Conveniently, a visual indication of the dose that may be
dialed, for example reference numerals (not shown). is provided on
the outer surface of the dose dial sleeve 70. The Window 44
conveniently only allows to be viewed a visual indication of the
dose currently dialed.
[0064] A second end of the dose dial sleeve 70 is provided with an
inwardly directed flange in the form of number of radially
extending members 75. A dose dial grip 76 is disposed about an
outer surface of the second end of the dose dial sleeve 70. An
outer diameter of the dose dial grip 76 preferably corresponds to
the outer diameter of the main housing 4. The dose dial grip 76 is
secured to the dose dial sleeve 70 to prevent relative movement
therebetween. The dose dial grip 76 is provided with a central
opening 78. An annular recess 80 located in the second end of the
dose dial grip 76 extends around the opening 78.
[0065] A button 82 of generally `T` section is provided at a second
end of the pen-type injector. A stem 84 of the button 82 may extend
through the opening 78 in the dose dial grip 76, through the inner
diameter of the extension 38 of the drive sleeve 30 and into the
receiving recess 26 of the piston rod 20. The stem 84 is retained
for limited axial movement in the drive sleeve 30 and against
rotation with respect thereto. A head 85 of the button 82 is
generally circular. A skirt 86 depends from a periphery of the head
85. The skirt 86 is adapted to be seated in the annular recess 80
of the dose dial grip 76.
[0066] Operation of the pen-type injector in accordance with the
present invention will now be described. In FIGS. 9, 10 and 11
arrows A, B. C, D, E, F and G represent the respective movements of
the button 82, the dose dial grip 76, the dose dial sleeve 70, the
drive sleeve 30, the clutch means 60, the clicker 50 and the nut
40.
[0067] To dial a dose (FIG. 9) a user rotates the dose dial grip 76
(arrow A). With the clicker 50 and clutch means 60 engaged, the
drive sleeve 30, the clicker 50, the clutch means 60 and the dose
dial sleeve 70 rotate with the dose dial grip 76.
[0068] Audible and tactile feedback of the dose being dialed is
provided by the clicker 50 and the clutch means 60. Torque is
transmitted through the saw teeth 56, 66 between the clicker 50 and
the clutch means 60. The flexible arm 52 deforms and drags the
toothed member 54 over the splines 42 to produce a click.
Preferably, the splines 42 are dispose such that each click
corresponds to a unit dose.
[0069] The helical groove 74 on the dose dial sleeve 70 and the
helical groove 38 in the drive sleeve 30 have the same lead. This
allows the dose dial sleeve 70 (arrow C) to extend from the main
housing 4 and the drive sleeve 30 (arrow D) to climb the piston rod
20 at the same rate. At the limit of travel, a radial stop 104 on
the dose dial sleeve 70 engages either the first stop 100 or the
second stop 102 provided on the main housing 4 to prevent further
movement. Rotation of the piston rod 20 is prevented due to the
opposing directions of the overhauled and driven threads on the
piston rod 20.
[0070] The nut 40, keyed to the main housing 4, is advanced along
the intermediate thread 36 by the rotation of the drive sleeve 30
(arrow D). When the final dose dispensed position (FIGS. 4, 5 and
13) is reached, a radial stop 106 formed on a second surface of the
nut 40 abuts a radial stop 108 on a first surface of the second
flange 34 of the drive sleeve 30 preventing both the nut 40 and the
drive sleeve 30 from rotating further.
[0071] In an alternative embodiment (not shown) a first surface of
the nut 40 is provided with a radial stop for abutment with a
radial stop provided on a second surface of the first flange 32.
This aids location of the nut 40 at the cartridge full position
during assembly of the pen-type injector.
[0072] Should a user inadvertently dial beyond the desired dosage,
the pen-type injector allows the dosage to be dialed down without
dispense of medicinal product from the cartridge (FIG. 10). The
dose dial grip 76 is counter rotated. This causes the system to act
in reverse. The flexible arm 52 now acts as a ratchet preventing
the clicker from rotating. The torque transmitted through the
clutch means 60 causes the saw teeth 56,66 to ride over one another
to create the clicks corresponding to dialed dose reduction.
Preferably the saw teeth 56,66 are so disposed that the
circumferential extent of each saw tooth corresponds to a unit
dose.
[0073] When the desired dose has been dialed, the user may then
dispense this dose by depressing the button 82 (FIG. 11). This
displaces the clutch means 60 axially with respect to the dose dial
sleeve 70 causing the dog teeth 65 to disengage. However the clutch
means 60 remains keyed in rotation to the drive sleeve 30. The dose
dial sleeve 70 and associated dose dial grip 76 are now free to
rotate (guided by the helical rib 46 located in helical groove
74).
[0074] The axial movement deforms the flexible arm 52 of the
clicker 50 to ensure the saw teeth 56,66 cannot be overhauled
during dispense. This prevents the drive sleeve 30 from rotating
with respect to the main housing 4 though it is still free to move
axially with respect thereto. This deformation is subsequently used
to urge the clicker 50, and the clutch 60, back along the drive
sleeve 30 to restore the connection between the clutch 60 and the
dose dial sleeve 70 when pressure is removed from the button
82.
[0075] The longitudinal axial movement of the drive sleeve 30
causes the piston rod 20 to rotate though the opening 18 in the
insert 16, thereby to advance the piston 10 in the cartridge 8.
Once the dialed dose has been dispensed, the dose dial sleeve 70 is
prevented from further rotation by contact of a plurality of
members 110 (FIG. 14) extending from the dose dial grip 76 with a
corresponding plurality of stops 112 formed in the main housing 4
(FIGS. 15 and 16). In the illustrated embodiment, the members 110
extend axially from the dose dial grip 76 and have an inclined end
surface. The zero dose position is determined by the abutment of
one of the axially extending edges of the members 110 with a
corresponding stop 112.
* * * * *